A KNX switching function only requires one Group Address. This Group Address links the switching object(s) of the rocker(s) with the switching object(s) of the relay(s).

OptionalA switching function can additionally have a status-feedback feature. This is a Group Address that links a status object (LED) of the rocker with the feedback object of the relay. Both the status object and the feedback object have a data length of 1 bit.